Their car was found soon after but the driver was still being sought.
The crash took place between Allenby Rd and Birdwood Ave, and Great South Rd was closed on Friday night while the Serious Crash Unit investigated.
Couillault said the boy’s friend witnessed the crash and was assisting police with their investigation. There were also other witnesses on the street at the time.
The boy’s death had a profound impact on the school and local community, he said.
“It’s just darkness and despair. There is a lot of sadness - teachers, family, his besties.
“We are going to have to work hard to support those that need it.”
The school had this morning divided students up into groups, depending on how well they knew the student, for meetings with counsellors today.
The Ministry of Education has offered its support to the school.